Yearly millions of pounds of polyethylene terephthalate (PET) go into the production of fabricated products such as containers, e.g., bottles, food containers, films, fibers and the like. This makes the resin an attractive material for recycling. In fact, there exists today a large business based on the recycling of PET. One drawback, however, to the known recycling techniques is that of being able to recover what is known in the industry as "clear" PET. Instead much "colored" PET is recovered. The colored material contains dark streaks or specs caused by the decomposition of glue and other foreign material upon melting of the PET (such as when processed into pellets for further use). The "colored" PET contains glue which was employed to adhere labels and bases to the containers. "Colored" PET has more limited uses than "clear" PET which can be refabricated into products which do not contain dark colors. Clear PET can be used to make fibers for clothing, insulation fiber fill, fish line, fabrics and other similar products.
Present known methods for recovering PET from containers and the like involves first mechanically removing non-PET solids such as metal bottle caps from a mixture thereof, and then forming the material into flakes containing PET, glue, labels (paper, etc.), and residue (e.g., soda pop) from the contents of the container. The flakes are then subjected to a sink/float separation in water and/or air to float off some of the less dense material such as paper and dissolve some of the residue contents (e.g., beverages) in water. The PET flakes sink along with some coated paper. The PET flakes are then subjected to one or more hot washings containing surface active agents, etc., to remove more paper and some of the glue. These methods are generally limited to the recovery of "colored" PET.
The present invention is directed to the recovery of "clear" PET from PET formed products, e.g., bottles, containers, film, etc., which are contaminated with a glue. The invention is also useful since solvent may be recovered.